Follow the instructions to set keyboard shortcut:

• Open Preferences Dialog 
• Switch to the tab named 'Keyboard'
• From listed shortcuts, focus on the one you like to set
• Make sure that checkbox is checked to set the shortcut
• Select one of the ALT | CTRL | ALT+CTRL
• Then select virtual key from letters A-Z or numbers 0-9

To learn more about provided keyboard shortcuts, check related help topics.